title: Diffusion tensor imaging detects rarefaction of optic radiation in glaucoma patients.
abstract: OBJECTIVE
  Diffusion tensor imaging (DTI) can depict rarefaction of the optical fibres. Hence, we applied DTI to assess pathological changes of the optic radiation in glaucoma patients.
  
  
  METHODS
  Fifty glaucoma patients and 50 healthy age-matched controls were examined by a 3T high-field magnetic resonance scanner. Fiber tracts were volume rendered using a semiquantitative approach to assess rarefaction and results were correlated with the extent of optic nerve atrophy and reduced spatial-temporal contrast sensitivity of the retina using established ophthalmological examinations.
  
  
  RESULTS
  Twenty-two glaucoma patients (44%) showed significant rarefaction of the optic radiation: the volume was reduced to 67 ± 16% compared with controls. Hereby, the glaucomatous optic nerve atrophy stage correlated with the presence of DTI-derived rarefied optic radiation (Kendall tau-b 0.272, P = .016). Aside, cerebral microangiopathy affecting the optic radiation was significantly higher among glaucoma patients compared to controls (10 patients compared with 2 patients, P < .05).
  
  
  CONCLUSIONS
  In patients with glaucomatous optic nerve atrophy, there is anterograde and-most likely because of microangiopathic lesions within the optic radiation-retrograde transneuronal rarefaction of the optic radiation that can be assessed in vivo using DTI with good correlation to established ophthalmological examinations.
authors.affiliation: Department of Neuroradiology, University Erlangen-Nuremberg, Germany. tobias.engelhorn@uk-erlangen.de
authors.forename: Tobias
authors.initials: T
authors.lastname: Engelhorn
authors.forename: Georg
authors.initials: G
authors.lastname: Michelson
authors.forename: Simone
authors.initials: S
authors.lastname: Waerntges
authors.forename: Tobias
authors.initials: T
authors.lastname: Struffert
authors.forename: Sultan
authors.initials: S
authors.lastname: Haider
authors.forename: Arnd
authors.initials: A
authors.lastname: Doerfler
mesh_terms: D000368:Aged; D001284:Atrophy; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005901:Glaucoma / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity